Multiposition control handle having detent means



Aug. 25, 1970 P. E. OLSON MULTIPOSITION CONTROL HANDLE HAVING DETENT MEANS 7 Filed Oct. 20, 1967 3 Sheets-Sheet l INVENTOR. PAULEOLSON ATTORNEY P. E. OLSON Aug. 25, 1970 MULTIPOSITION CONTROL HANDLE HAVING DETENT MEANS Filed Oct. 20, 1967 3 Sheets-Sheet 2 N mo TS mL v mE ATTORNEY Aug. 25, 1970 P. E. OLSON MULTIPOSITION CONTROL HANDLE HAVING DETENT MEANS Filed Oct. 20, 1967 3 Sheets-Sheet 5 INVENTOR. PAUL E. OLSON ATTORNEY United States Patent ice US. Cl. 74530 4 Claims ABSTRACT OF THE DISCLOSURE A multiposition control handle having detent means in which a handle operated control shaft in a housing is detented for axial rotation to different control positions by a pair of axially toothed detent members, one member of which is nonrotatably mounted in the housing and axially movable into intermeshed engagement with the other member which is coaxially disposed on the shaft for axial rotational movement therewith. In one embodiment the teeth on the detent members are V-shaped so that rotation of the shaft in either direction earns the housing-mounted member oppositely relative to a constantly applied bias to provide overriding, sliding or ratcheting movement between the teeth as the shaft is moved from one control position to the other. In other embodiments the detent members are normally biased apart and the teeth are of saw-tooth shape to provide only uni-directional rotation of the shaft when the clutch members are electrically or pneumatically engaged.

Heretofore, when a handle operated control device was to be mounted upon appartus to be controlled at different speeds of operation, it has been difficult to provide handle detenting which would maintain the handle in selected positions in opposition to vibration of the operating apparatus, and yet provide relatively easy shifting of the control mechanism from one position to another.

Accordingly, it is the object of the present invention to provide in a handle operated control device a detenting mechanism providing a relatively large detenting force while providing easy movement from one control position to the other.

In the present invention, this object is achieved by disposing in a housing a handle operated multiposition control shaft detented for axial rotation to different control positions by a pair of axially toothed detent members, one member of which is non-rotatably mounted in the housing and axially movable into toothed engagement with the other member which is coaxially disposed on the shaft for axial rotational movement therewith. The teeth on each member are axially extending and are arranged in a circular train concentric with the axis so that when the members are biased into engagement, rotary movement of the shaft is effected from one detented position to another by applying to the handle a shaft rotating force, having a component transmitted by the pitch of the teeth to oppose and exceed the bias, for effecting overriding sliding or ratcheting movement of the teeth of the shaft-mounted member relative to the teeth of the housing-mounted member during movement of the" shaft to a different rotary position.

In one embodiment the detent members are biased into engagement and the teeth are V-shaped to provide detented bidirectional rotary movement of the shaft. In other embodiments the teeth are saw-tooth shaped and the members are biased to separate until the occurrence of certain operating conditions in the controlled apparatus whereupon the members are electrically or pneumatically engaged so that the saw teeth provide detenting which Patented Aug. 25, 1970 permits rotary movement of the shaft in only one direction. a

This and other objects of hte invention will become more readily apparent in the following description, taken with the drawing in which:

FIG. 1 is an elevational view taken partly in section, of a handle operated control device showing my invention;

FIG. 2 is a cross-sectional view of one of the detent members shown in FIG. 1, as taken along line 2-2 of FIG. 3;

FIG. 3 is a top view of the detent member shown in FIG. 2;

FIG. 4 is a side elevational view of the toothed member shown in FIG. 2;

FIG. 5 is a cross-sectional view of another detent member as shown in FIG. 1;

FIG. 6 is a side elevational view of the detent member of FIG. 5;

FIG. 7 is an elevational view, taken partly in section, of another embodiment of the invention;

FIG. 8 is an elevational view, taken partly in section of yet another embodiment of the invention;

FIG. 9 is a side elevational view of one of the detent members shown in FIG. 8; and

FIG. 10 is a top plan view of the detent member shown in FIG. 9. v

In order to illustrate the applicability of the present invention to a particular multiposition controlled device, reference is made to FIGS. 1-6 of the drawing showing .the detenting assembly 1 of the present invention in cooperative environmental association with a rotary valve device 2. The cooperating structureand function of the stator 3 and rotor 4 of the rotary valve are intended merely as illustrative of one of many types of multiposition control devices, and since the details thereof 'are not necessary to the understanding of the invention, such description is omitted as immaterial, it being necessary to note .only that the rotor 4 is selectively positionable in any one of a plurality of rotary control positions in accordance with the position of the multiposition control assembly 5. However, reference is made to Pat. No. 3,048,675, patented Aug. 7, 1962 by P. E. Olson et al., for a detailed description of such structure and its particular utility, for example, to operate a fluid motor which in turn may operate a power transmission.

Referring now to FIG. 1 in particular, it will be seen that a housing 6 is attached to one side of the aforementioned stator 3 by any suitable means such as screws 7, only one shown, which housing encloses therein the aforementioned rotor 4 engaging the stator, and a support member 8 having a central through bore 9 supporting the aforementioned control assembly 5. The aforementioned detenting mechanism 1 is disposed in a bottomed bore 10 in an auxiliary housing 11 attached to the side of housing 6 by any suitable means such as screws 12, only one shown, with the left end of the auxiliary housing extending within housing 6 through an aperture 13 centrally disposed in the right end of the housing so as to dispose the bottomed bottom bore 10 in coaxial alignment with bore 9 in support 8.

The control assembly 5 includes an axially rotatable shaft member, generally indicated at 14, comprised of three integral portions, of which, a first or right end portion comprises a pair of transversely spaced axially extending members 15, only one being shown, a second or intermediate cylindrical portion 16 disposed in a bearing 17 fixed in bore 9 and having therein an axially extending bottom bore 18 opening between the aforementioned pair of members 15, and a third or left end portion 19 comprising a transverse flange overlying the left end of support member 8 and attached to the rotor 4 by means of pins 20 so that axial rotation of the shaft member 14 effects corresponding axial rotation of the rotor.

In order to provide axial rotation of the shaft member, an operating handle 21 has one end disposed between the pair of members 15 and pivotally attached thereto by a transverse pin 22 extending through the handle and the shaft pair of members 15, with the other end of the handle extending exteriorly of the housing through a transverse slot 23 in one side of housing 6.

In order to provide for resiliently disposing the handle 21 in a predetermined pivotal position about pin 22 so as to extend transversely of the shaft member through the slot in a laterally centered position transversely of the slot, as shown, there is provided a handle return assembly comprising a cylindrical member 24 biased to the right in bore 18 of the shaft member 14 by a spring member 25, and an integral transverse member 26 on one end thereof laterally extending between the pair of members 15 in longitudinal engagement with the handle 21, the opposite ends of the transverse member providing handle return leverage when the handle is released after being pivoted about pin 22 in either direction for a purpose hereinafter described.

In order to provide a setting for each control position of the operating handle 21, the housing is provided with a first row of pins 27 extending rightwardly into the slot 23 and a second row of pins 28 extending leftwardly into the slot, with the pins spaced along the slot length so that the pins of each row are staggered relative to the other. Each pair of pins 27, 28 are spaced along the slot a distance slightly greater than the thickness of the handle 21 to thus define therebetween an operating position for the handle, and the free ends thereof are transversely spaced a distance less than the thickness of the handle to prevent movement of the handle along the slot 23 from one operating position to the other, unless the handle is moved to the left or right or from the aforementioned centered position against the bias of the handle return mechanism to clear the rightwardly extending or leftwardly extending row of pins, respectively.

In now describing a first embodiment of the detenting means for holding the shaft 14 and handle 21 in any setting in opposition to vibration tending to move the handle and shaft, it will be observed by reference to FIGS. 1-6 that the shaft detenting assembly 1 comprises a pair of cylindrical detent members 29, 30 cooperating to provide detenting of the axially rotatable shaft member 14 relative to the housing 6.

Referring now to FIGS. 2, 3 and 4 of the drawing, it will be seen that detent member 29 is generally cylindrical in form and includes on one end face thereof a series of identical V-shaped teeth 31 disposed circumferentially around the outer edge of the end face. The flat crests 32 of the teeth are axial extensions of the detent member relative to the valleys 33 between the teeth and are each longitudinally disposed in a radial direction relative to the axis of the detent member. The slope of each tooth face is constant throughout the breadth of the tooth so that the sides of valleys and crests of the teeth are oppositely sloped relative to a plane transversely intersecting the axis of the detent member so as to be disposed along radii of a single point disposed in the plane and on the axis of the detent member, in known manner, to facilitate maximum engagement of the teeth faces of one detent member with the corresponding teeth faces of the other detent member during camming movement there-; between. An axially disposed pressure balancing through bore 34 in detent member 29 is provided with a counterbore so that when the detent member 29 is installed in bore of auxiliary housing 11, as shown in FIG. 1, a spring member 35 is compressed between the bottom of the counterbore of bore 34 and a depression 36 in housing 11 to bias the detent member axially leftwardly, as shown. An axially extending groove 37 is provided exteriorly of the member, as best seen in FIG. 4, which groove, when the member 29 is installed in auxiliary housing 11, longitudinally registers with a corresponding groove 38 in the wall of bore 10 to form a bore into which a pin 39 is inserted to comprise a key mechanism preventing axial rotation of detent member 29 relative to bore 10 while at the same time providing for free axial movement of the detent member 29.

Referring now to FIGS. 5 and 6, it is seen that detent member 30 is generally cylindrical in form and includes on one end face thereof a series of teeth 40 having a form and relative disposition identical to that of teeth 31 on the above-described detent member 29 to facilitate intermeshing of teeth 31 with teeth 40, in the manner shown in FIG. 1. In order to fix the detent member 30 to the right end portion 15 of the shaft member 14 for axial rotation therewith, the end face opposite the teeth 40 is provided with an axially disposed bottomed bore 41 transversely intersected by a groove 42 of rectangular crosssection and having a width less than the diameter of the bore 41, as best seen in FIG. 6, so that when a correspondingly shaped pin member 43 (as seen in FIG. 1) is disposed in the groove 42, a space is provided in bore 41 on each side of the pin 43 sufiicient to receive therein the laterally spaced pair of members 15 in straddling relationship relative to pin member 43. A cylindrical member 44 is press fitted over the end of cylindical detent member 30 to hold the pin 43 fixed in the detent member 30. A pin member 45 extends through the cylindrical member 44, pin 43 and detent member 30 to complete the assembly of the detent member 30 on the end of shaft 14. An O-ring seal member 46 is disposed in an annular groove 47 to prevent the intrusion of dirt into bore 10 in auxiliary housing 11.

In now describing the operation of the device of FIGS. 16, as above described, it is assumed that the handle 21 is in the position shown so that the rotor 4 is in a rotary position relative to the stator 3 effecting a control operation, such as to operate a power transmission, not shown, in one of its operating conditions. If vibration of the vehicle engine or motion of the vehicle should oscillate the handle 21 in a direction transversely of slot 23 tending to periodically dispose the handle so as to laterally clear the pins 26 or 27, and tend to rotate the rotor 4 relative to the stator 3, the biasing force of spring 35 engages teeth 31 of detent member 29 with teeth 40 of detent member 30, thus holding the shaft 14 in the rotary position shown.

If now it is desired to rotate shaft 14 to another rotary position to thereby rotate rotor 4 to a different control position, that is for example, to shift the power transmission to another gear range, the handle 21 is first manually moved to the left or right to clear a pin 27 or 28, respectively, depending on the desired rotary direction of shaft 14, and thereafter a force is applied to the handle to move the handle along slot 23 to the next pin 27 or 28. When the shaft rotating force is applied to the handle, the teeth 40 of detent member 30' transversely apply to teeth 30 of detent member 29 a shear sheer force having a vertical component of force which cams detent member 29 rightward in overriding opposition to biasing spring 35 whereupon detent member 29 moves rightwardly until the crests of teeth 40 slide past the crests of teeth 31 whereupon further rotary movement of shaft 14 provides a gradual intermeshing of the teeth via reverse action of biasing spring 35 until the teeth are fully intermeshed to complete one camming cycle. The aforementioned camming cycle and overriding sliding engagement of teeth 40 relative to teeth 31 repeatedly occurs at the rate of one camming cycle for each movement of the shaft through a distance of one tooth width until the handle is disposed laterally against the next pin 27 or 28, whereupon the handle is again moved leftwardly or rightwardly to clear the pin 27 or 28, and thereafter is further moved back until finally centered between a pair of the pins 27, 28 in another control position. The handle is released, whereupon the handle return mechanism 24, 25 and 26 disposes the handle in the neutral position, as shown in FIG. 1, between the selected pair of pins 27, 28, and the detent members 29, 30 are fully reengaged via operation of biasing spring 35 to thereby hold the handle in the newly selected position. From the foregoing, it will be seen that the V-shaped cross-section of the teeth 31 and 40 provides for movement of the handle and shaft in both rotary directions of the shaft.

Referring now to FIGS. 8, 9 and of the drawing, there is shown a second embodiment of the invention in which a modified detenting assembly generally indicated at 48 is disposed in housing 49, 52 to effect detenting action relative to the control assembly generally indicated at 50, the latter being disposed in housing 49 to axially rotate a rotor member 51 relative to a stator member not shown.

In this embodiment, the rotor 51 and stator each carry a plurality of electrical contacts, not shown, which, when the rotor is axially rotated, make or break in different combinations to provide different electrical control signals in accordance with the axial position of the rotor relative to the stator, such as for electrically shifting gears in a power transmission in a manner heretofore known in the art. Since the particular structure of the contacts is not a part of the invention and is not necessary to the understanding of the invention, the detailed description thereof is omitted. Moreover, it is readily seen that the contacts of the present embodiment and the rotary valve device of FIG. 1 are readily interchangeable merely as a matter of choice, without affecting the invention.

The control assembly 50 is substantially identical to the corresponding assembly of FIG. 1 and accordingly will not again be described except with respect to differences in structure. Specifically, the connector means between the control assembly 50 and the rotor 51 in the present embodiment comprises a transversely disposed axially protruding tab member 53 on the rotor 51 en gaged in a correspondingly shaped slot 54 in the left end of the shaft member 14 previously described in FIG. 1 of the drawing. The shaft member 14 is prevented from moving axially relative to support member 8 by way of a snapring 55 disposed in a groove on shaft 14 to overlie a radial lip 56 on previously described bearing member 17.

The detenting mechanism 48 of the present embodiment comprises, as before, a pair of coaxially disposed detent members 57, 58 each having a series of teeth 59, 60, respectively, on the adjacent end faces for interrneshing engagement. However, in this embodiment the afore mentioned teeth are saw-tooth shaped in cross-section, rather than V-shaped, and the detent members are normally biased apart, as shown in FIG. 8, so that-the teeth are completely disengaged.

Referring now to FIGS. 9 and 10 in particular, it is seen that detent member 57 is generally cylindrical in form and comprises a left portion carrying the aforementioned saw-tooth shaped teeth 59 on the end face thereof, each tooth having an axially extending vertical side 61 and a sloped side 62. Thus it is seen that the teeth 59 are arranged on the end face in a manner similar to the teeth described in the embodiment of FIG. 1, except that the teeth are saw-tooth in cross-section rather than -V-shaped, for purposes hereinafter described. A pair of transversely opposing flats 63 are provided on the right end portion for mating with a corresponding pair of oppositely disposed flat surfaces 64, respectively, in a counterbore 65 of bore 66 disposed in a right extension 67 of housing 49, so that detent member 57 is disposed for axial and non-rotatable movement relative to extension 67. The right end portion of detent member 57 is smaller in diameter and comprises a piston slidably received in the aforementioned bore 66 and carries on its periphery an O-ring seal for pressure sealing the right end of bore 66. A fluid pressure passage 68in extension 67 communicates with bore 66 for pressurization of the bore to move the detent member 57 leftward under certain conditions, as hereinafter described. A bottom bore 69 is provided in the left end of clutch member 57 to receive one end of a biasing spring 70.

The detent member 58 includes on the right end surface teeth 60 identical in structure to teeth 59 on detent member 57, and is attached to the right end of shaft 14 in the same manner as previously described detent member 30 in the embodiment of FIG. 1. The central bore 71 in clutch member 58 is a through bore coaxially aligned with bottom bore 69 in detent member 57 so that the left end of spring 70 axially engages the right end of shaft 14. Since shaft 14 is axially immovable in support member 8, spring 70 biases detent member 57 rightwardly to the position shown in which the shoulder 72 between the right and left portions of detent member 5-7 axially engages shoulder 73 formed between bore 66 and counterbore 65, in which position the teeth 59, 60 of detent members 57 and 58 are completely disengaged, as shown in FIG. 8.

In now describing the operation of the embodiment of FIGS. 8, 9, and 10, it is assumed that the fluid pressure in bore 66 is at a minimum or zero so that the greater force of spring 70 biases detent member 57 rightwardly to the position shown to completely disengage teeth 59 and 60. Under this condition, handle 21 is freely movable along the rows of pins 26 and 27, in the manner previously described, to axially rotate shaft 14 in either rotary direction to effect different control operations, with positioning of the shaft in any selected position being effected solely by pins 26 and 27.

If now it is assumed that bore 66 is pressurized to such an extent as to provide a force overriding the bias of spring 70, detent member 57 is moved leftwardly to intermesh teeth 59 with teeth 60 of clutch member 58. Under this condition, when manual force is applied to the handle to rotate shaft 14 and detent member 58 in a direction to press the sloped sides of teeth 60 on detent member 58 laterally against the correspondingly sloped sides 62 of teeth 59 on detent member 57, detent member 57 is cammed rightwardly, in the manner previously described with respect to FIG. 1, to provide overriding sliding or ratcheting movement of teeth 60 relative to teeth 59 as the handle is moved to the new control position. It is to be specifically noted, however, that if manual force is applied to handle 21 to rotate shaft 14 and detent member 58 in the opposite rotary direction, the horizontal sides of teeth 60 press against the horizontal sides 61 of teeth 59 at a right angle relative to the rotary force, thereby preventing the occurrence of any horizontal component of force operable to cam clutch member 57 rightwardly. Therefore, detent member 58, shaft 14 and handle 21 are locked relative to reverse rotary movement.

In now describing one practical application of the embodiment of FIGS. 8, 9, and 10, it will be assumed that the electrical contacts of the stator, not shown and rotor 51 are connected to control a conventional power transmission, not shown, on a motor vehicle, not shown, in various gear ranges in accordance with the axially rotated position of the rotor 51 relative to the stator, not shown. As is well-known, when the engine of a vehicle is operating at a speed commensurate with the selected gear range, the associated conventional power transmission assumes a lock-up condition, during which condition a down-shifting operation of the transmission to a lower gear range could cause damage to the vehicle or the transmission. It is also well-known that certain passage means in the transmission are pressurized only during this condition. Accordingly, when the passage or port 68 in housing extension 67 is connected via piping, not shown, to the aforementioned pressurizable passage means in the transmission, fluid pressure will be applied to bore 66 to effect engagement of clutch members 57, 58 during, and only during, the occurrence of the lock-up condition. Therefore, by arranging the operating positions of handle 21 in a sequence to provide progressive upshifting operation of the transmission in the hereinbefore described ratcheting direction of movement of detent member 58 relative to detent member 57, the saw-tooth configuration of teeth 59 and 60 assures that upshifting from any forward gear to another is always possible, while downshifting from any forward gear to another is prohibited only during the lock-up condition. When the lock-up condition is eliminated, such as occurs when the speed of the vehicle reduces due to heavier engine loading, the bore 66 is accordingly depressurized, detent member 57 is then disengaged from detent member 58 via operation of biasing spring 70, whereupon the handle 21 and shaft 14 are freed for movement in either rotary direction and may now be moved in the opposite rotary direction, that is, in the downshifting direction to select a more appropriate lower gear range, as desired.

Referring now to FIG. 7 of the drawing, there is shown yet another embodiment of the invention, in which a modified detenting assembly, generally indicated at 74, controls movement of a rotary control assembly 75 which in turn controls an electrical contact assembly comprised of a rotor 76 and a stator 77.

The rotor 76, stator 77 and control assembly 75 are identical to the corresponding parts described above with respect to FIGS. 8, 9, 10, and accordingly reference is made to the description of those figures for details of construction.

The detent assembly 74 of this embodiment serves the same function as the detent assembly above described with respect to FIGS. 8, 9, 10, but is of a different structure so as to be operable in response to an electrical signal rather than a fluid pressure signal.

Accordingly, a solenoid housing 78 is attached to the right end main housing 79 by any suitable means, not shown, and includes therein a solenoid comprised of coils -80 wound on a spool 81, and a plunger member 82 disposed in the center of the spool to move leftwardly in response to energization of coils 80 by an electrical signal transmitted thereto through wires 83. An axially extending plunger extension 84 extends leftwardly through an aperture 85 in solenoid housing 78 into a coaxially disposed bore 86 to operate the detent mechanism in the manner hereinafter described.

The detent assembly comprises a pair of detent mem bers 87, 88, each having on one end face thereof sawtooth shaped teeth 89, 90, respectively, having the configuration and arrangement identical to the hereinbefore described teeth 59, 60 on the detent members 57, 58 as shown in FIGS. 8, 9, and of the drawing.

Detent mem ber 88 is identical to detent member 58 of FIG. 8 and is attached to the right end of shaft 14 in the same manner.

Detent member 87 is cylindrical in form and is disposed for axial movement in bore 86. A pin 91 disposed between the housing 78 and detent member 87 prevents axial rotation of the detent member relative to the housing in the same manner as shown in FIG. 1 of the drawing. A pair of axially opposing bottom bores 92, 93 are centrally disposed in detent member 87 separated by a transverse wall 94. A spring 95, disposed in bore 93, is compressed between the right end of shaft 14 and wall 94 to normally bias detent member 87 rightwardly to the position shown to disengage the detent members 87, 88. A spring member 96 is disposed in bore 92 in compression between wall 94 and a plate 98 transversely disposed relative to and normally in abutting relationship with the left end of plunger extension 84. A snap ring 97placed 'within bore 92 rightwardly overlies the periphery of plate 98 to limit spring 96 relative to detent member 87 so that when the solenoid is deenergized, detent member 87 is biased to the rightward limit by spring 95 as shown, and plunger 82 is biased to the rightward position by spring 96, as shown,

In now describing the operation of the embodiment of FIG. 7, it is assumed that the solenoid is deenergized, and that detent members 87, 88 are disengaged, as shown in FIG. 7. Under this condition, handle 21 may be moved in either direction along slot 23 to axially rotate shaft 14 in either rotary direction to selectively perform dilferent control operations, such as changing gear ranges in a power transmission, as described above with respect to FIG. 8.

It it is now assumed that a lock-up condition occurs within the transmission, a fluid-pressure operated electrical switch, not shown, will provide a corresponding electrical current in wires 83 to energize solenoid windings 80. Plunger 82 and plunger extension 84 are urged leftwardly to compress spring 96, providing a leftward force transmitted by wall 94 to compress spring 95 so that detent member 87 is moved leftwardly into engagementwith detent member 88. Under thiscondition, upon the application of manualforce to handle 21 to eifect rotary movement of detent member 88 in the previously described upshift direction relative to detent member 87, that is, in the ratcheting direction in which the sloped sides of teeth 90 are pressed laterally into engagement with the sloped sides of teeth 89, detent member 87 is cammed rightwardly, compressing spring 96 against the end of plunger extension 84 as teeth 90 override teeth 89. It is seen that spring 96 provides for resilient reciprocable axial movementfiof detent member 87 relative to the plunger extension 84 during the aforementioned camrning action while the plunger 82 and extension 84 remain in a fixed leftwardly extended position established by energization of the solenoid windings.

By analysis with the practical application described for the operation of the embodiment of FIG. 8, it will be seen that so long as the windings are energized by the lockup condition in the transmission, movement of the han-' dle 21 and shaft 14 in the previously described downshift direction is prohibited by engagement of the horizontal sides of the saw-teeth 89, on clutches 87, 88 respectively.

Having now described the invention, what I claim as new and desire to, secureby Letters Patent is:

1. A multiposition control means having detent means, comprising:

(a) shaft means axially rotatable relative to a support means for selective disposition in a plurality of rotary control positions;

(b) a detent means comprising first and second detent members each having teeth thereon axially interrneshable with the other;

(c) said first detent member concentrically fixed to saidshaft means;

(d) said second detent member disposed on said support means for coaxial movement into detenting engagement with said first detent member;

(e) means preventing axial rotational movement of said second detent member relative to said support means; m

,(f) means for axially biasing said second detent member into detenting engagement with said first detent member;

(g) said teeth having a configuration such as to cam apart said first and said second detent members in overriding opposition to said biasing means when said shaft is rotated about its axis;

(h) spring means normally biasing said detent members to disengage;

(i) said means for biasing said detent members into axial engagement disposed to opposingly override said spring means; and J g (j) said teeth have 'a configuration such that when intermeshed preventaxial rotation of said first detent memberrelative to said second detent member for one direction of axial rotation of said first detent member.

2. A multiposition control means having detent means, as recited in claim 1, in which said means for biasing said detent members into axial engagement comprises:

(a) a fluid pressure chamber on said support means;

and

(b) fluid pressure operated piston means on said second detent member operable for movement into axial engagement with said first detent member in response to pressurization of said fluid chamber.

3. A multiposition control means having detent means,

as recited in claim 1, in which:

,(a) said means for biasing said first and said second detent members into axial engagement comprises a solenoid mounted on said support, and;

(b) said solenoid including a plunger operable to axially move said second detent member into engagement with said first detent member 'when the solenoid is energized.

4. A multiposition control means having detent means,

as recited in claim 3, in which, a spring means is disposed between said plunger and said second detent member.

References Cited UNITED STATES PATENTS 594,946 12/1897 Grossman 74-471 3,048,657 8/1962 018011 et al 74 533 X 3,128,635 4/1964 DOOlittlC 74-471 2,821,091 1/1958 Benner. 3,204,734 9/1965 McMaken.

3,090,458 5/1963 Wolf 74 847 X 3,139,766 7/1964 Granryd 74-843 FOREIGN PATENTS 7,819 5/1915 Great Britain.

FRED C. MATTERN, JR., Primary Examiner C. F. GREEN, Assistant Examiner US. Cl. X.R. 74-471, 528, 533 

